EFFECTS OF EXTERNAL RESISTANCE ON DENITRIFICATION AND CARBON REMOVAL PERFORMANCE OF A MICROBIAL FUEL CELL USED IN SIMULATED GROUNDWATER

Nitrate pollution in groundwater has become a serious concern worldwide. However, the studies of using the microbial fuel cell (MFC) of porous medium system to treat nitrate in groundwater have seldom been reported previously. This study investigated the electricity production performance and denitrification of a large-volume single-chamber MFC used in porous medium system. The results showed that the device exhibits good performance of nitrogen and carbon removal and electricity generation in the MFC of porous medium system with 800 Omega external resistance. The COD removal rate was 57.6%, and nitrate nitrogen value remained at a very low level in the whole operation cycle. The maximum output voltage was 413 mV, and the voltage remained about 300 mV after the experiment. The maximum power density was 56.36 mW/m(2) and the corresponding current density was 187.68 mA/m(2). The dominant microbial communities attached on the carbon cloth electrodes were Fluviicola taffensis, Flavobacteriales bacterium, Moraxellaceae Bacterium, Acinetobacter sp, Flavobacterium SP, Paracoccus kawasakiensis, Hirschia baltica.